Routine HIV testing of inmates when they enter jails would lead to many more diagnosed infections and overall would save costs on health care, a recently published study says.

Researchers from the Centers for Disease Control and Prevention, Emory University and the Georgia Department of Public Health focused on an HIV testing change at the Fulton County Jail in Atlanta.

Three years ago, the jail switched from routine testing of inmates to a more random process. That led to dozens of missed HIV diagnoses over the course of a year, according to the study, published in November in the American Journal of Preventive Medicine.

The Atlanta area “has a high prevalence of HIV, and much of it is undiagnosed,’’ said Dr. Anne Spaulding, associate professor of epidemiology at Emory’s Rollins School of Public Health, who is one of the authors of the study. “Very few jails have done routine testing’' as Fulton County once did, she added.

The Southeast in general is now the center of the disease in this country.

But the current public health focus on COVID-19 has disrupted HIV prevention and treatment services, according to UNAIDS Executive Director Winnie Byanyima.

Clinics have limited in-person visits, and doctors’ offices and emergency rooms have halted routine HIV screening, Kaiser Health News reported in April.

“There’s clearly a problem in the dropoff in testing because of COVID,” said Phyllis Kanki, professor of immunology and infectious disease at the Harvard T.H. Chan School of Public Health, who has studied HIV in Africa.

Incarcerated people have HIV rates that are three to 10 times those of the general U.S. population. Many have lacked regular access to health care, Spaulding said. “HIV now is a disease that has a disproportionate effect on individuals who are suffering from economic inequities.”

Prior to 2018, the Fulton County Jail sought to test all incoming inmates, though an individual could opt out of the screening.

The study found that in the year beginning in March 2013, the routine testing found 74 more new HIV infections than in 2018, when the random procedure began. The change in testing caused an estimated 8.4 additional HIV transmissions and $3.7 million in additional costs to the health care system, the study said.

Early diagnosis can get individuals into care more quickly, preserving their immune systems and making them less likely to transmit HIV.

“There are so few things in health care that are cost-saving,” Spaulding said. “Testing in jails requires public health agencies and correctional agencies to be working together.’’

As a result of the study, the Fulton jail’s health program manager, Tracey Elam, said in a statement the jail is “actively exploring’' resuming its routine HIV testing policy.

“If you treat too late, if the person’s immune system has begun to have damage from the infection, . . . [eventually ] you have huge health care costs,” Kanki said.

One jail that does routine testing for HIV, along with hepatitis C and STDs, is in Washington, D.C., through medical provider Unity Health Care.

“We focus on continuing treatment or starting treatment if needed for our patients living with HIV as well as connecting them to care upon release through our discharge planning services,’’ said Dr. Eleni O’Donovan, medical director of correctional health for Unity, a federally qualified health center.

A jail won’t immediately save money because of an HIV testing program — and it may even see its expenses go up, said Dr. Josiah Rich, professor of medicine and epidemiology at the Warren Alpert Medical School of Brown University. But the long-term reduction in spending can be significant, he added.

Local jurisdictions should take advantage of the mass incarceration numbers with HIV testing and patient education, Rich said, instead of taking what he called an “ostrich approach’' toward jail inmates.

“If you have a lot of HIV in a community, you want to diagnose all you can. That will prevent further spread.’’

Andy Miller is editor of Georgia Health News.